By David Yoel, founder and CEO, American Aerospace Advisors (www.american-aerospace.net), Radnor, Pa.

Unmanned aircraft systems (UASs) have proved to be valuable assets for the warfighter. Today, they’re emerging as new and potentially useful tools for civil and humanitarian applications.

UASs range in size from near-microscopic aircraft to aircraft the size of commercial jets. Each type offers its own benefits, but in general the value revolves around several key capabilities: the ability to operate in dangerous conditions without putting pilots in harm’s way,
endurance far greater than is possible with manned aircraft, and providing a cost-effective alternative to fixed and rotary wing aircraft in terms of maintenance and per-hour operation costs.

Just as manned aviation proved its value in World War I, the initial market for UASs is military. The 1920s saw the growth of civilian and commercial applications with the advent of airmail and passenger transport. Today, civilian aviation accounts for more than 70 percent of the world market, with military at about 27 percent.

Some believe a similar future awaits unmanned aviation.

UASs are rapidly emerging as new and potentially useful tools for Earth imaging. Currently, the Federal Aviation Administration (FAA) is working with lawmakers and the UAS industry to develop regulations that will enable routine operations in the National Airspace System (NAS) for Earth imaging applications, including emergency management, precision agriculture and environmental sciences (see "UAS Technology Promises Widespread Benefits,” page 30).

UASs Come in All Shapes and Sizes

UAS configurations range from traditional fixed-wing aircraft to rotary-wing copters to micro-UASs that mimic the flight mechanics of birds. At the upper end, the Northrop Grumman Global Hawk is the most prominent aircraft, with a 131-foot wingspan, 60,000-foot service ceiling and at least 28-hour endurance. The aircraft reportedly can survey 100,000 square kilometers a day. Approximately 45 Global Hawks have been produced to date.

In the medium-size range one encounters a larger number of aircraft types from the Shadow, a U.S. Army UAS produced by AAI with a 100-pound payload capacity, to the RS-16, a UAS developed by American Aerospace Advisors with 25-pound payload capacity and 12+ hours endurance. As of 2012, the Shadow has logged more than 750,000 flight hours to support military missions.

This class of aircraft typically has altitude ceilings in the 15,000-foot range and endurance ranging from 6 to 20 hours. Their moderate payload capacity generally is inadequate to accommodate the traditional survey-grade mapping systems used today.

At the small end of the spectrum, the number of micro-aircraft seems to be doubling each day, some no larger than a tennis ball. There’s a fascinating array of experimental systems exploding onto the market, ranging from the AeroVironment Nano Hummingbird to the do-it-yourself drone movement.

All of these systems are unmanned in that there’s no one on the aircraft. It’s important to note, however, that there’s always at least one individual responsible for operating the aircraft. This is why some people prefer the name remotely piloted vehicle instead of UAS.

In the case of the miniature systems, typically only one person is required for safe operation. As aircraft increase in size, the number of people required to operate the systems also increases. This is more of an issue for civilian and commercial UAS use than it is for military applications, because economics often reigns as the higher priority.

An example of a development direction that’s not reminiscent of the manned aviation industry, and that may lead to reduced crew sizes in the future, is seen in the work of the General Robotics, Automation, Sensing and Perception Lab at the University of Pennsylvania, which is focused on “swarming drone technology” as famously presented at the 2012 TED Conference (www.ted.com/talks/vijay_kumar_robots_that_fly_and_
cooperate.html).

One of the reasons the acronym UAS has taken hold is the emphasis on the “S,” which points to the fact that the aircraft is part of a system. In fact, for most medium and large UASs, the greater part of the system resides on the ground. This includes radio systems, launchers, capture systems, computers and ground control stations. When operating in the NAS, the safety impacts of each system element must be understood, not just the airborne component.

Adapting New Sensors to UASs

As interesting as UASs can be, they’re simply platforms for carrying systems and sensors needed to perform tasks such as Earth imaging. The aircraft segment of UAS technology account for a small percentage of the overall system required to perform useful tasks and conduct safe and effective operations in the NAS.

There are several significant challenges associated with integrating sensors onto unmanned aircraft. For example, in medium- and small-sized aircraft, limited mass, volume and power must be accommodated in the design of sensor packages. In addition, because the aircraft are often smaller than manned aircraft, sensor systems are located in closer proximity to radios, causing greater exposure to interference. Unmanned aircraft engines literally can be inches from a sensor, and there’s less mass in the aircraft to dissipate vibration.

One of the traditional uses of UAS technology in military applications is intelligence, surveillance and reconnaissance (ISR). In general, the sensor packages used in ISR are different than those optimized for Earth imaging. Therefore, new sensor systems are required to take advantage of UAS technology’s unique capabilities.

Trimble’s acquisition of Gatewing may be a leading indicator of the industry’s direction. A survey-grade mapping solution, the company’s UX5 UAS weighs 5.5 pounds (2.5 kilograms) and operates for approximately 50 minutes carrying a 16-megapixel camera.

American Aerospace Advisors, with its partner Ecliptic Enterprises, has developed a multispectral QuickMaps payload for medium-altitude, long-endurance UASs, such as the RS-16. The five-band system has been used for mapping salt marshes on the Gulf of Mexico, fire mapping, conducting animal inventories at national parks, monitoring oil and natural gas pipeline corridors, and mapping power line
corridors after hurricanes.

Integrating UASs into Civilian Airspace

In February 2012, the FAA Modernization and Reform Act was signed into law. One rather small element of the bill was the introduction of a
Sept. 30, 2015, deadline to integrate UASs into the NAS. Of course, congress didn’t provide funding to support this requirement. Given the amazing range of UAS sizes, weights and types, the challenge of defining safe flight standards and protocols represents a significant challenge that will require extensive evaluation.

One of the key technical challenges that must be addressed before truly routine “file and fly” flight operations can be considered is the development of sense-and-avoid technologies. Normally, a manned aircraft pilot has ultimate responsibility for seeing and avoiding other aircraft. UAS technologies that replace a pilot’s ability to scan for other aircraft are in development, with several showing promise. Although it’s not likely the 2015 deadline will be met because of the complexity of the task, FAA is working diligently to develop flight regulations for operating in the NAS. Above all, flight safety reigns as top priority.

In the interim, there are two mechanisms for legally flying UASs in the NAS. The first is the Certificate of Waiver or Authorization (COA). COAs are available to “public entities” that have a “public purpose” to fly a UAS. Public entities include federal, state and local government agencies and state universities. Public purposes can include things such as public safety, emergency response and scientific research.

Obtaining a COA typically takes six to 12 months. A COA is issued for a particular type of aircraft, operated in a specific area, under approved operating procedures and conditions. Once approved, a COA is valid for one year. During that time, flight operations can be conducted simply by contacting local Air Traffic Control one week in advance and filing a Notice to Airmen.

For commercial enterprises there’s an alternative to the COA known as the Special Airworthiness Certificate UAS. Also referred to as an “Experimental,” this permit lets commercial companies conduct UAS research and development, testing, crew training and market surveys. Such permits are issued for a specific aircraft at a specific location, with a specific flight crew, and therefore have limited utility for Earth imaging.

Another key challenge is the complexity of the NAS. In many parts of the world, airspace regulatory compliance isn’t a high priority and routine operations can be readily conducted. But in terms of civil UAS integration, the world is flat. Time will tell whether the more rapid pace of growth in UAS operations outside the United States will have a negative effect on domestic manufacturers or whether the additional cost, complexity and time required to integrate UAS into more complex airspace will someday become a competitive advantage.

Regardless, during the early discovery phase, the UAS community has explored a variety of innovative applications.
Although many challenges lie ahead, including the development of airspace regulations, the development of unmanned aircraft designed for civilian applications and new sensor systems adapted to these air vehicles, UAS technology is destined to play an increasing role in Earth imaging, bringing many new and exciting applications yet to be discovered.

Captions

The Hornet Micro supports a wide range of missions, capturing real-time video and high-resolution digital images from any position.

High-altitude, long-endurance UASs, such as the RQ-4 Global Hawk and the modified Predator B NASA Ikhana aircraft, shown above, have been modified for use in multiple civil research roles.

The RS-16 is a medium-altitude, long-endurance UAS designed for civilian applications in the National Airspace System.

Equipped with a small video camera for surveillance and reconnaissance purposes, the Nano Hummingbird is a tiny remote-controlled aircraft built to resemble and fly like a hummingbird.

It took years for the U.S. military to appreciate the value of unmanned aircraft systems (UASs). Now the technology’s appeal has expanded for a wide variety of civilian uses. Some of the most promising applications are highlighted in the sections below.

Emergency Management

Responding to natural disasters is expected to be an early market for UASs because they have the potential to increase the safety and effectiveness of first responders without putting pilots in harm’s way. This may include responding to hurricanes, tornados, floods, wildland fire, avalanches and search-and-rescue operations, to name a few.

In wildland fire applications, for example, UASs can be used to locate fires and help assess their intensity. They can provide communications relay over the ridge and over the horizon. Large fires can change the weather, and UASs also hold promise as tools to collect data for improved weather forecasting.

Emergency operations call for quick-response flight operations and near real-time production of data products such as fire maps. Among the many challenges of deploying UASs in emergencies, this implies the need for high-bandwidth radio links for data transport from the aircraft to the ground where imagery is processed and then disseminated.

In pioneering work performed by NASA and the U.S. Forest Service, the Ikhana UAS, a General Atomics Predator B optimized for civil environmental science and technology, has proved successful for fire mapping missions.

Caption: Thermal-infrared imaging sensors on NASA's Ikhana UAS recorded this image of the Grass Valley/Slide Fire in Southern California’s San Bernardino Mountains. Active fire is seen in yellow, while hot, previously burned areas are in shades of dark red and purple. Unburned areas are shown in green hues.

Precision Agriculture

For centuries, the fundamental unit of production in agriculture has been the field. Within the field, inputs such as water, pesticides and fertilizer are applied uniformly. But inputs are applied variably from field to field. If inputs are applied only where needed, there’s the potential to reduce the overall use of labor, fuel, pesticide, fertilizer and water without diminishing yield. Because agriculture is a business that operates on razor-thin margins, any reduction in inputs has the potential to improve profit margins significantly.

UASs hold great promise in increasing the use and reducing the cost of precision agriculture.
For example, companies like John Deere and Novariant are producing ground-based variable-rate application equipment. In the air, the Yamaha RMAX unmanned helicopter offers benefits such as reduced spraying and seeding, remote sensing, precision agriculture, frost mitigation and variable rate dispersal.

Caption: University of California-Davis researchers tested a remote-controlled helicopter to spray pesticides on vineyards, which normally are sprayed using ground vehicles.

Environmental Sciences

The planet is evolving rapidly, as is our understanding of the processes and mechanisms driving the changes. From satellites to manned aircraft, scientists are eager for better ways to collect Earth data. UASs have the potential to let Earth scientists reach farther afield more efficiently and safely.

For example, the U.S. Geological Survey’s National Unmanned Aircraft Systems Project Office has been established to support the integration of UAS technology into the processes employed by the agency’s scientists to support informed decision making across the Department of the Interior. One of the key benefits of this work is expected to be “… an increased level of persistent monitoring of Earth surface processes (forest health conditions, monitoring wildfires, earthquake zones, invasive species, etc.) in areas that have been difficult or nearly impossible to obtain information before.” For more information on the agency’s UAS activities, see “USGS UAS Program Does More with Less,” page 12.

Another area of great promise is the use of UAS in environmental science.
For example, researchers at Texas A&M University Corpus Christie have been using an RS-16 UAS to carry a multispectral payload over coastal areas to develop techniques to understand water quality, salt marshes and fish populations.

Caption: The U.S. Geological Survey, Boise State University and the University of Idaho partnered to use UAS technology to gather data on the landscape habitat of pygmy rabbits (insets), which depend on sagebrush.